There was no reason for yesterday's strike by care workers represented by the IMPACT trade union, according to the Minister for Health, Mr Martin.
"I'm at a loss to explain why IMPACT refused to defer the strike action when the Labour Court issued a full invitation to them to come in for a full hearing tomorrow and actually gave a very strong commitment to all sides that they would have recommendations within 10 days of Sunday last."
He rejected the suggestion that he had failed to intervene in the dispute until the last moment.
The Opposition last night accused Mr Martin of going back on his word to offer better pay to hundreds of carers of patients with intellectual disabilities.
Demanding that he intervene to end the strike, the Labour Party's equality spokesperson, Ms Jan O'Sullivan, said Mr Martin was "directly responsible" for it.
Last April, the Department of Health told health boards that all carers were to be paid the same, but the offer was restricted in a subsequent circular, she alleged.
"This is the crux of the issue and the Minister has clearly gone back on his word. The only way to end the distress of hundreds of families is for the Minister to provide the necessary funding to health service employers to honour the agreement. Reversing a decision like this is unprecedented."
Mr Martin said on RTÉ that a Department of Health circular issued last April dealt specifically with childcare workers operating in secure units only.
"There is a dispute about the scope of that particular agreement," said Mr Martin. "We are very clear as to who it applied to and there was not an attempt to discriminate against anybody. It was entered into in good faith because of the crisis in childcare."
For Fine Gael, Ms Frances Fitzgerald said the Minister's first contact with IMPACT union representatives came at 12.15 a.m. on Monday morning, just hours before staff began to withdraw their labour.
"It is beyond belief that he did not try to avert this strike earlier."